Scientists develop infinitely recyclable plastic material

New polymer, PDK, has the potential to create a sustainable, closed loop ecosystem in the plastic industry

Scientists at the Berkeley Laboratory published a report in April of this year announcing the development of a new polymer called polydiketoenamine, or PDK. The material represents an alternative to plastic that can be easily broken down at the chemical level and fully reconstructed. This has scientists and environmentalists alike excited about the potential usage of polymers in packaging that are infinitely recyclable.

An accidental discovery

Plastic is made up of polymers, which are compounds of hydrogen and carbon obtained from petroleum refining. These polymers are composed of smaller strands called monomers, which combine with specific chemicals to create the final material. Scientists at the Berkeley Lab were experimenting with different monomers and chemicals and happened upon an exciting breakthrough.

According to lead author Brett Helms, the eureka occurred while picking up after their experiments. “While cleaning our glassware with acids, we realized that a chemical reaction was taking place.” After further inspection, they discovered that they had, by accident, broken down the bonded polymers completely into their original chemical compounds. This presented the potential for a completely recyclable plastic, which can be deconstructed and chemically re-assembled. All it takes is a little room temperature acid.

Power of PDK

PDK presents an exciting breakthrough because it can be broken down at the molecular level and recycled into virgin-quality polymer without any loss of quality. Scientifically, it can be “depolymerized into its individual monomers and then remade,” explains Rachel O’Reilly from the University of Birmingham, UK. This allows it to be “upcycled” back into itself quite easily – allowing for infinite recycling without any material loss or significant reduction in quality.

As a result, PDK shows the potential for a sustainable, closed loop system in which 100% of the plastic material could be recovered, broken apart like Lego™ bricks, and rearranged into brand new plastic material. What’s more exciting is that the recovery and reuse process for PDK is significantly easier and more efficient than the current recycling process for plastics. No industrial incineration facilities required. “They just require a few minutes in a ball mill,” explains Helms, and then the new polydiketoenamines can be created with a simple mixture at room temperature.

Closed loop systems

The potential for a true closed loop with plastic is an extremely exciting prospect for both scientists and environmentalists. Closed loop systems are the gold standard when measuring sustainability within manufacturing and commercial processes, as the successful recovery and reuse of materials significantly reduce waste.

Closed loop processes depend upon the materials themselves, as the development of PDK clearly highlights. Most plastics are not designed for reuse or easy recyclability, and, as a result, pose a serious problem once they reach the end of their short lifespans. EPE is leading the trend with packaging designs that avoid using materials which are difficult to recover or recycle, such as EPS. And we are constantly researching scientific developments and new sustainable materials that allow for further reduction of our environmental footprint.